For all questions and bookings, please call our reception on (03) 9077 9912
We're available Monday To Friday 08:00am - 06:00pm AEST

Select Language English Chinese (Simplified)

Thunderstorm Asthma Season Is Here — What Every Melbourne Resident Needs to Know

Every year from 1 October to 31 December, Melbourne enters a period that health authorities take seriously enough to run a dedicated daily forecasting system. It’s called thunderstorm asthma season — and it’s something that affects far more Melburnians than most people realise.

You don’t need to have been diagnosed with asthma to be at risk. You just need to get hay fever.

If spring in Melbourne means sneezing, itchy eyes, or a runny nose for you — this post is worth reading. Here’s what thunderstorm asthma is, who it can affect, what the 2026 season is looking like, and what you can do right now to protect yourself.

What is thunderstorm asthma?

Thunderstorm asthma isn’t regular asthma triggered by bad weather. It’s a specific phenomenon that occurs when two things happen at the same time: high grass pollen levels in the air, and a particular type of thunderstorm.

Here’s what happens at a biological level. Thunderstorm asthma is thought to be triggered by a unique combination of high amounts of grass pollen in the air and a certain type of thunderstorm. During that storm, pollen grains are swept up into the upper atmosphere where moisture causes them to rupture and burst into thousands of much smaller particles. Those particles are then swept back down to ground level — small enough to bypass your nose and upper airways and penetrate deep into your lungs.

For someone whose immune system is sensitised to grass pollen — essentially anyone with springtime hay fever — this can trigger a sudden and sometimes severe asthma attack, even if they’ve never had asthma before.

Research shows that grass pollen is by far the most common cause of spring hay fever (seasonal allergic rhinitis) in Victoria. The specific grass thought to be involved in epidemic thunderstorm asthma events in Victoria is ryegrass.

Grass pollen data collected in Melbourne for more than 20 years shows that the highest levels start occurring, on average, in mid-October and fluctuate daily until the end of December.

Why Melbourne?

Melbourne has a unique and unfortunate combination of factors that make it one of the most thunderstorm-asthma-prone cities in the world. The surrounding grasslands produce large quantities of ryegrass pollen each spring. Melbourne also experiences dramatic weather changes — the kind of fast-moving storms that create the atmospheric conditions required for the phenomenon to occur.

Who is at risk of thunderstorm asthma?

This is the part most people get wrong. Thunderstorm asthma is not just a concern for people with diagnosed, severe asthma. The risk is significantly broader.

You may be at risk if you:

  • Have hay fever symptoms during spring — sneezing, itchy eyes, runny nose (even mild)
  • Have been diagnosed with asthma at any point in your life, even if you haven’t needed a puffer in years
  • Have mild or intermittent asthma that is not currently well controlled
  • Have never been formally diagnosed with asthma but have occasionally felt wheezy or tight-chested during spring
  • Are allergic to ryegrass pollen

People with allergic rhinitis and allergy to ryegrass pollen — the majority of people with springtime allergic rhinitis symptoms — are at risk of thunderstorm asthma if they live in, or are travelling to, a region with seasonal high grass pollen levels

The key warning sign is this: if your hay fever ever comes with wheeziness, chest tightness, or shortness of breath — even mildly — that’s your body telling you something important. You are not simply a hay fever sufferer. You are someone thunderstorm asthma can hit hard.

Groups at particularly high risk include:

  • People with asthma who are allergic to ryegrass pollen and are not currently using an inhaled corticosteroid (ICS) preventer
  • People with uncontrolled or under-treated asthma
  • People with hay fever who have never been assessed for underlying asthma
  • People who rely only on a reliever (blue Ventolin) puffer without a preventer

Symptoms — what does thunderstorm asthma feel like?

Thunderstorm asthma can develop very quickly — sometimes within minutes of exposure to storm-affected air. Symptoms can range from mild to life-threatening.

Early symptoms:

  • Wheezing (a whistling sound when breathing)
  • Chest tightness or pressure
  • Shortness of breath, particularly with exertion
  • Coughing — especially a persistent dry cough
  • These symptoms alongside hay fever (sneezing, runny nose, itchy eyes)

Severe symptoms — call 000 immediately:

  • Severe difficulty breathing
  • Unable to speak in full sentences
  • Blue tinge to lips or fingernails
  • Unresponsive or losing consciousness
  • Reliever puffer not providing relief

If you or someone around you develops sudden breathing difficulty during or after a thunderstorm between October and December — treat it as a medical emergency and call 000.

What to do before, during, and after a storm

Before a storm — prepare now, not when you see lightning

Check the forecast daily. The epidemic thunderstorm asthma risk forecast operates between 1 October and 31 December. It combines the forecasting of a certain uncommon type of thunderstorm and grass pollen levels across Victoria. It spans three days (today, tomorrow, and the day after) and uses a colour-coded scale from low to high risk: green (low), orange (moderate) and red (high.

The forecast is available via:

See your GP before the season peaks. If you have hay fever, a history of asthma, or have ever experienced wheezing or chest tightness during spring — book a GP appointment now, before high-risk days arrive. Your GP can:

  • Assess your risk and confirm whether you have underlying asthma
  • Review or prescribe a preventer inhaler (ICS) if appropriate
  • Write or update your asthma action plan
  • Ensure your reliever puffer is in date and you know how to use it correctly with a spacer

Make sure your medication is current and accessible. A reliever puffer that expired two years ago, or that’s sitting in a drawer at home when you’re at work in the CBD, won’t help you during a storm. If you’re not sure whether your puffer is current or appropriate, see your GP.

During a storm — act fast

Where possible, avoid being outside during thunderstorms from October through December — especially in the wind gusts that come before the storm. Go inside and close your doors and windows, and if you have your air conditioner on, turn it to recirculate.

The most dangerous period is not the storm itself — it’s the wind gusts immediately before the rain arrives. If you’re outdoors and see a storm approaching during pollen season, go inside immediately. Don’t wait.

If you develop symptoms: use your reliever puffer immediately.

After the season — review and follow up

A thunderstorm asthma season is the ideal time to establish an ongoing relationship with a GP for your respiratory health. After the season:

  • Book a review to assess how you managed
  • Discuss whether your preventer medication was adequate
  • Consider allergy testing to confirm ryegrass pollen sensitivity
  • Ask about immunotherapy (desensitisation) if you have severe hay fever — this can reduce your sensitivity over time

Asthma action plans — what they are and why you need one

An asthma action plan is a written plan prepared by your GP that tells you exactly what to do when your asthma symptoms change. It sets out:

  • Your normal medications and doses
  • What symptoms mean your asthma is worsening

An asthma action plan doesn’t cost much. It takes one GP appointment. It could save your life.

Thunderstorm asthma and undiagnosed asthma

If you recognise yourself in that description — hay fever with occasional wheeziness, chest tightness, or a persistent cough in spring — it’s worth having a conversation with your GP about whether underlying asthma is present. A spirometry test (a simple breathing test) can be performed and gives your GP objective information about your lung function.

Identifying and treating underlying asthma before a thunderstorm asthma event is one of the most effective protective measures available.

When to see a GP about thunderstorm asthma risk

Book a GP appointment at CBD Doctors Melbourne now if:

  • You have hay fever and have never been assessed for asthma
  • You have asthma but haven’t reviewed your management plan in the last 12 months
  • You are relying solely on a reliever (blue) puffer — with no preventer medication
  • You’ve experienced wheeziness or chest tightness during spring in the past
  • Your reliever puffer is expired or you’re not sure how to use it correctly
  • Your children have hay fever or asthma and you want their management reviewed before the season

Don’t wait for a high-risk forecast day to sort this out. When a red forecast hits, GP appointment books fill up fast. Prepare now.

Book a same-day appointment at CBD Doctors Melbourne

CBD Doctors Melbourne is located at Level 10, 53 Queen Street, Melbourne CBD — between Collins Street and Flinders Lane, easily accessible from across the CBD and inner suburbs including Southbank, Docklands, Carlton, Fitzroy, and East Melbourne.

Same-day appointments are available for asthma reviews and hay fever management. No referral required. The doctors can refer for spirometry test if needed.

Frequently asked questions

Can you get thunderstorm asthma if you’ve never had asthma? Yes. Anyone with hay fever caused by grass pollen sensitivity — the majority of spring hay fever sufferers in Melbourne — can experience thunderstorm asthma, even without a prior asthma diagnosis.

When is thunderstorm asthma season in Melbourne? The official season runs from 1 October to 31 December each year. The Victorian Department of Health operates a daily thunderstorm asthma risk forecast throughout this period, available via VicEmergency and Melbourne Pollen.

What should I do if I get symptoms during a thunderstorm? Go indoors immediately, close windows and doors, and use your reliever puffer with a spacer. Follow your asthma action plan if you have one. Seek medical attention if symptoms are severe, worsening rapidly, or not improving with your reliever.

How do I know if I need a preventer inhaler? If you use your reliever puffer more than twice a week, if your symptoms wake you at night, or if you have hay fever with any chest symptoms — see a GP. A preventer inhaler significantly reduces your risk of severe thunderstorm asthma and is available on the PBS.

Where can I check the thunderstorm asthma forecast? The three-day epidemic thunderstorm asthma risk forecast is available daily throughout the season on the VicEmergency website and app (em.vic.gov.au), health.vic.gov.au, and the Melbourne Pollen website (melbournepollen.com.au) and app.

Can a GP prescribe a preventer puffer at a same-day appointment? Yes. CBD Doctors Melbourne GPs can assess your asthma risk, prescribe preventer medication, and write an asthma action plan at a same-day appointment. Book online today

Book an appointment in Melbourne CBD

CBD Doctors Melbourne is located at Level 10, 53 Queen Street, Melbourne CBD — between Collins and Flinders Lane, easily accessible by tram, train, and car.

Getting here:

  • Tram: Collins Street (Routes 11, 12, 48, 109)
  • Train: Flinders Street Station (5 minutes walk), Southern Cross Station (10 minutes walk)
  • Car: Paid parking on Queen Street, William Street, and the Rialto car park on Collins Street

Same-day appointments are available Monday to Friday.

Book Appointment